I'd take a faster lens over a few mm any day of the week. Do you have the 18-55mm canon kit lens? If so that covers your higher end wide angle and you can use the tokina for REALLY wide fisheye looking shots.

I see... Its cheaper and seems like the build quality is better on the tokina. After this wide angle I think I will go for the 17-40mm L lens or the 18-55mm IS version. I ditched the kit lens a long time ago lol.

After having used it for a while now, i have noticed that the Tokina is no where near as sharp as the canon 10-22. Maybe i just got a bad copy or something, but at 100 crop, its noticeably less sharp then the 10-22. I still think the lens is great "bang for buck" and having a faster lens is truly helpful when shooting at night. But if i had to pick one or the other, im not so confident i'd pick the 11-16 again.

All the ultrawides vary some from copy to copy. The 10-22 and 11-16 both have reputations as being the sharpest of the bunch. Even so the edges are never going to be spectacular. I only have direct experience with the 10-22, but found two copies to give pretty identical results - at 10mm very good in the center, but only OK at the edges even stopped down to f/11. Somewhat better and more uniform sharpness out beyond 12 or 13mm.

Don't get me wrong. I've had the 10-22 for 4 years now and use it lots. It's a fine landscape lens on 1.6x Canon bodies, but it's not a 21mm Distagon or a Nikon 14-24. Don't get your expectations too ridiculously high and you'll be happy with the 10-22 (or, from what I've heard, the 11-16).